1. Field of the Invention
The present invention relates to a server client system and, more specifically, to an improvement of a port setting in a network audio system operating in a server client environment.
2. Description of the Related Art
At the present day, a network audio system operating in a server client environment has been provided. The network audio system is provided with a content server for storing musical contents and audio clients for reproducing the music. The content server and the audio clients communicate with each other in accordance with a specific communication protocol.
For example, in the case of adopting TCP/IP (Transmission Control Protocol/Internet Protocol) as a communication protocol, each of the content server and the audio clients is provided with a unique IP address in a network. The content server and the audio clients identify each other due to the IP address. In addition, the content server and the audio clients have a plurality of ports for transmitting and receiving the data. The TCP/IP allocates port numbers of 0 to 65535 to these ports.
When the audio client requests something to the content server, the audio client specifies the IP address and the port number of the content server to transmit the data to the specified content server through the specified port. On the contrary, when the content server responds to the request of the audio client, the content server specifies the IP address and the port number of the audio client to transmit the data to the specified audio client through the specified port.
In order to allow the above-described data transmission and reception, normally, one port is enough between the content server and the audio clients; however, depending on an application program, sometimes a plurality of ports must be saved. In this case, a user needs to set a plurality of port numbers not only for the content server but also for each audio client. However, it is a very troublesome task to set a plurality of port numbers for each of many audio clients existing on a network and this may result in a high probability of setting a false port number.
In addition, for the reason such as version upgrade of the application program or the like, the port numbers to be used sometime must be altered. Also in this case, as the above, it is very troublesome to alter the port numbers set in each audio client.
In addition, when the other application program other than an original application program is installed in the content server, the other application program sometime uses a port number to be used by the original application program. Also in this case, it is very troublesome to alter the port numbers set in each audio client.